13. A new gene for resistance to gallmidge in rice variety Abhaya

M.N. SRIVASTAVA, Arvind KUMAR, S.K. SHRIVASTAVA and R.K. SAHU

Indira Gandhi Agricultural University, Raipur 492012, M.P., India

We studied mode of inheritance of resistance to gallmidge in rice variety Abhaya. This variety is resistant to new biotype of gallmidge (biotype-4) which emerged in 1986 in Eastern Andhra Pradesh, India. Varieties and segregating populations were screened under field conditions at Raipur. The level of infestation was very high as the susceptible parents showed 100% infestation on single plant basis (Table 1).

The F2 populations from the crosses of Abhaya with susceptible varieties segregated in the ratio of 3 resistant to 1 susceptible (Table 1) indicating that Abhaya has one dominant gene for resistance. The F2 populations from the crosses of Abhaya with gallmidge resistant varieties Samridhi, Ruchi, and Phalguna segregated in a ratio of 15 resistant to 1 susceptible (Table 1). Samridhi and Ruchi have Gm-1 for resistance and Phalguna has Gm-2 for resistance (Choudhary et al. 1986). These results show that the gallmidge resistance gene of Abhaya is nonallelic to Gm-1 and Gm-2. This gene is probably differenet from the recessive gene for resistance, gm-3 identified in ARC5984 (Sahu et al. 1990). This new gene is designated as Gm-4(t).


  Table 1. Reaction of parents and F2 populations for gallmidge
resistance
============================================================================
                             Reaction to Plants
Parents/Cross            ----------------------------  Expected ratio   X2  
                         Resistant       Susceptible        (R:S)
                           (No.)            (No.)
============================================================================
Kranti                      0                76               -         -
Annda                       0                71               -         -
Tulsi                       0                75               -         -
Ratna                       0                81               -         -
Cheptigurmatia              0                77               -         -
Abhaya                     75                 0               -         -
Samridhi                   80                 0               -         -
Ruchi                      78                 0               -         -
Phalguna                   67                 0               -         -
Abhaya/Tulsi              584               191               3:1    0.052
Abhaya/Annda              375               104               3:1    2.762
Abhaya/Kranti             449               150               3:1    0.0005
Abhaya/Cheptigurmatia     411               117               3:1    2.273
Abhaya/Samridhi           581                33              15:1    0.810
Abhaya/Ruchi              621                39              15:1    0.931
Abhaya/Phalguna           510                36              15:1    0.110
============================================================================

References

Choudhary, B. P., P.S. Shrivastava, M.N. Shrivastava and G.S. Khush. 1986. Inheritance of resistance to gallmidge in some cultivars of rice. In Rice Genetics. p. 523-528. International Rice Research Institute, P. O. Box 933, Manila, Philippines.

Sahu, V. N., R. Mishra, B.P. Choudhary, P.S. Shrivastava and M.N. Shrivastava. 1990. Inheritance of resistance to gallmidge in rice. RGN 7: 118-121.